Percentage Calculator
Calculate X% of Y, what percent X is of Y, or the percent change from X to Y — three common percentage questions, one tool, instantly, in your browser.
Find a percentage of a number, what percent one number is of another, or the percentage change between two values. It runs in your browser.
How to use it
- Choose a mode: “of”, “what percent” or “change”.
- Enter the two values. In “change” mode, X is the old value and Y the new one.
- Read the sentence it gives.
The three questions
- Of: 15% of 240 = 36.
- What percent: 45 is 25% of 180.
- Change: from 80 to 100 is an increase of 25%; from 100 to 80 is a decrease of 20%.
Good to know
The same gap gives different percentages in each direction, because each change is measured against its own starting value. Y cannot be zero in the “what percent” and “change” modes. A rise of 10% followed by a fall of 10% ends at 99% of the original, not 100%.
The percentage guide covers the formulas and common mistakes.
FAQs
What is the difference between percent and percentage points?
If a rate moves from 4% to 5%, that is 1 percentage point but a 25% increase.
How do I find the original number before a percentage increase?
Divide the new value by 1 plus the rate. A price of 130 after a 30% rise started at 130 ÷ 1.30 = 100.